In general, a beverage maker is a device which is adapted to make a beverage, for example on the basis of a quantity of water and a quantity of beverage extract, wherein the water is conducted through the beverage extract. A beverage maker which is adapted to make a beverage on the basis of a quantity of water and a quantity of beverage concentrate, wherein the water and the beverage concentrate are mixed, is also well-known. A beverage maker may be equipped with means for heating the water in order to be capable of supplying hot beverages.
When a beverage maker is operated, a quantity of water that is needed for the purpose of performing a process of making a beverage is pumped out of the water tank of the beverage maker. Usually, this water tank is removably arranged, so that it is easy for a user of the beverage maker to take the water tank and fill it with water. The pumping action is performed by means of a pump, wherein an energizing circuit of the beverage maker comprises a pumping circuit for energizing the pump. When the pumping circuit is closed, the pump performs the pumping action, and when the pumping circuit is interrupted, the pumping action is terminated. For the purpose of closing or interrupting the pumping circuit, the beverage maker comprises at least one switching device.
In a process of making a beverage, a quantity of the water that is used in the process in relation to a quantity of extractable material or concentrate is an important factor. For example, in the case of a process of preparing coffee on the basis of a quantity of ground coffee beans and hot water, a proportion between the quantity of ground coffee beans and a quantity of hot water that is conducted through the ground coffee beans is determinative of the strength and aroma of the coffee. Therefore, it is important that the quantity of hot water that is that is conducted through the ground coffee beans is accurately controlled.
Methods for controlling the quantity of water that is used for the purpose of preparing a beverage on the basis of a predetermined quantity of extractable material or a predetermined quantity of concentrate are known. In many cases, a beverage maker is equipped with a controlling circuit which is adapted to operate the pump in such a way that a total period during which the pump is operated corresponds to a predetermined period which is representative of a predetermined quantity of water.
For example, U.S. Pat. No. 6,000,317 discloses a coffee maker having a water reservoir for containing cold water, a heating chamber for heating a quantity of water, and a pump for pumping water from the reservoir through the heating chamber to a filter device. During operation of the coffee maker, the actuation of the pump is controlled by a control device. In U.S. Pat. No. 6,000,317, it is noted that if the entire content of the reservoir is to be brewed, a sensor which is responsive to the absence of water may be applied, wherein a signal of this sensor leads to a termination of the operation of the pump. Furthermore, in U.S. Pat. No. 6,000,317, it is noted that in case it is desired to use the coffee maker for preparing coffee by using only a portion of water from the reservoir, the coffee maker may be provided with a control selector for inputting-to the control device the desired quantity of coffee to be brewed. In such case, a flow detector may be provided in a flow path between the reservoir and the filter device, to measure the total flow of water during the process of preparing the coffee. The control device will deactivate the pump when a desired flow has taken place. Alternatively, it is possible that the operating time of the pump is controlled depending upon a desired quantity of coffee to be brewed.